* Biggest name to face trial so far in "Operation Yewtree" probe into UK celebrities

* Five decades at pinnacle of show business

* Four victims spoke of harrowing experiences (Adds quotes, details on sentence and other charges, background)

By Costas Pitas

LONDON, July 4 (Reuters) - Veteran entertainer Rolf Harris, a household name in his native Australia and adopted home Britain, was jailed for almost six years on Friday for repeatedly abusing young girls over decades as a beloved host of children's television.

Handing down the sentence, Judge Nigel Sweeney said the 84-year-old, known for shows such as "Rolf Harris Cartoon Time" and songs including "Two Little Boys", had shown no remorse for the harm he had done to his victims.

Harris was found guilty earlier this week of 12 counts of assaulting four girls, some as young as seven or eight, between 1968 and 1986.

It was the second conviction in a long-running investigation into sex abuse by British celebrities that has led to soul searching in the country, revealing that some of its most prominent stars of the 1970s and 1980s were serial paedophiles who evaded detection for decades.

"It is clear from the evidence that what you did has had a significant adverse effect on each victim," the judge told Harris, detailing how one woman had battled with alcoholism as a direct result of his abuse.

"You have shown no remorse for your crimes at all."

During two months of evidence, the court heard how Harris groped his victims, often while unsuspecting fans stood nearby.

"You clearly got a thrill from committing the offences whilst others were present or nearby," the judge said.

One victim said Harris had taken away her very "essence".

"I have never felt safe since. I live in a constant state of anxiety," she said in her statement, read out in court by a prosecution lawyer. "I know the person I am today is not the person I should have been."

An artist and musician who first earned fame in the 1950s with the top 10 hit novelty song "Tie Me Kangaroo Down, Sport", Harris went on to present prime-time TV shows mostly aimed at children during five decades at the pinnacle of show business.

In 2005 he painted Queen Elizabeth's portrait. Since Monday's guilty verdicts he has been stripped of several honours both in Britain and Australia.

Harris was the biggest name to go on trial since British police launched "Operation Yewtree" to investigate celebrity child abuse, following revelations two years ago that late BBC TV host Jimmy Savile had been a prolific child abuser.

On Friday, Harris sat motionless as the judge read out the sentence at a packed courtroom at London's Southwark Crown Court. He was later led from the dock, wearing a grey suit, white shirt and multi-coloured tie.

During the trial, the prosecution had portrayed the bearded, bespectacled entertainer as a predator who groomed and abused one woman for her entire teenage and young-adult life.

The London court was told he first assaulted the woman when she got out of the shower aged 13, and then repeatedly abused her until she was 28 years old.

WIDE-REACHING INVESTIGATION

Defence lawyer Sonia Woodley had asked for leniency due to the 84-year -old's health, age, his charity work and the ailing health of his wife, who has attended court most days but was not present on Friday.

In sentencing, Judge Sweeney said Harris would only have to serve half his five year and nine month sentence behind bars.

He also will not face four other, separate charges of making and possessing indecent images of children, which were not part of the trial and which he denies. Britain's Crown Prosecution Service decided it was no longer in the public interest to pursue those charges in light of this week's convictions.

Police launched the wide-reaching Operation Yewtree into historic sex crimes in the wake of the disclosures that Savile, who died in 2011 at 84, had managed to escape detection while abusing hundreds of children over the course of decades.

As one of Britain's best known celebrities, Savile had used his fame to gain access to victims and deflect suspicion, raising questions of whether other stars exploited a showbiz culture of impunity to abuse children in the 1970s and 1980s.

Since then, a dozen ageing British media luminaries have been the target of investigations over decades-old child abuse allegations.

The country's most well known publicist, Max Clifford, was found guilty in May of indecently assaulting teenage girls some 30 years ago as part of the investigation and sentenced to eight years in prison.

However, the police enquiries have been labelled a witch hunt by some of those placed under investigation, following decisions not to prosecute several high profile household names. (Writing by Kate Holton and Costas Pitas; Editing by Peter Graff)